An evolutionary analysis of economic hubs and transmission mechanisms for wastewater discharge

摘要: Due to the destruction of aquatic ecology and pollution of the water environment, policy formulation needs to pay more attention to factors other than economic benefits. Past research mainly relied on the average propagation lengths (APL) of wastewater discharge to empirically analyze the wastewater propagation between sectors. The hub sectors of wastewater discharge, which are densely-connected to other sectors, play key roles in reflecting wastewater discharge or wastewater treatment in the overall economic system. However, there is current ambiguity deficiency in analytic results of economic hubs and transmission mechanisms of wastewater discharge. At the same time, analyzing the transmission mechanism of wastewater discharge, proposing wastewater management and containment strategies are essential to sustainable development of water resource. This paper calculates the wastewater discharge APL based on the compiled sequential water input-occupancy-output tables of 49 sectors for 2002, 2007, 2012 and 2017 in China. Then, we introduce more broadly marginal dependence linkages into APL. A coupled model named APL-HCG (APL with hub covariance graph) is proposed to analyze the hub wastewater discharge sectors and hub propagation chains overall. The results illustrate the evolutionary pattern of the hub sectors of wastewater discharge and the transmission mechanism implicit in the key wastewater propagation chains nationwide from 2002 to 2017.